Poultry processing typically involves passing the birds through various equipment stations to stun, kill, and then bleed the birds. The still feathered poultry carcasses are then placed in a hot water bath or subjected to steam to heat the skin of the carcass in order to loosen the feathers. This heating process is commonly referred to as “scalding.” Once the feathers are loosened by the scalding step, poultry carcasses pass through defeathering equipment, and then the defeathered carcasses are eviscerated. The eviscerated carcasses are then typically chilled and packaged or passed on to further processing operations.
Although rinsing or washing steps may be performed prior to or during defeathering, and thereafter, bacterial contamination remains a serious problem in poultry processing. There may be a significant bacterial load along with all manner of filth on a bird's feathers at the start of processing. Fecal matter may be released from a bird's lower intestines in the scalding process or during defeathering. The fecal matter may contaminate the carcass or processing equipment, and may result in cross contamination with other carcasses. Particularly challenging are immersion-type scald tanks in which carcasses are immersed in a scald water held at a temperature typically between 120° F. and 140° F. The scald water in these tanks quickly becomes loaded with bacteria and filth which may find its way to the skin of the carcasses passing through the tank. Once on the skin of the carcass, the defeathering equipment may rub or massage the bacteria and filth in to the skin of the carcass, and particularly the openings left after feathers are pulled from the carcass. Once the bacteria is thus massaged into the skin of the carcass, it becomes more difficult to remove or kill.
Beyond the bacterial contamination problem associated with defeathering operations, the heat to which the carcasses are subjected preparatory to defeathering results in other problems. First, the heat applied during scalding may lower the quality of the skin on the carcass. Second, the heat applied during scalding increases the time and cost associated with later chilling operations. Additionally, there is the cost of heating the scald water, a cost made higher by having to constantly circulate in cleaned water in an effort to address bacterial loading in the scald water.
There remains a need for methods and apparatus that will reduce or eliminate the above problems and others associated with scalding and defeathering operations in poultry processing.